What is the source of P in tap water?

[EcoPit]

Does anyone know--is it present in the water source and does not get filtered out by the municipality before distribution, or do they add it as some part of the treatment process? (Or both, depending on the situation?) I don't actually have any in my tap water (as of now anyway), but I know many others do and was curious.

[reiverix]

IIRC phosphate is a corrosion inhibitor.

[EcoPit]

So it is specifically added. Interesting. Thanks John.

[beviking]

If you google for it, you find all kinds of things :)

Funny how Phosphate is suppose to be limited in natural systems...but is that from lack of nutrient or because it is so readily used by plants :idea2: